Acrylonitrile polymer compositions containing modified bentonite and fibers formed therefrom



United States Patent ACRYLONITRILE POLYMER COMPOSITIONS CON- TAININGMODIFIED BENTONITE AND FIBERS FORMED THEREFROM John R. Caldwell,Kingsport, Tenn., assignor to Eastman Kodak Company, Rochester, N.Y., acorporation of New Jersey No Drawing. Application April 7, 1954 SerialNo. 421,683

16 Claims. (Cl. 26030.4)

This invention relates to the manufacture of synthetic filaments andfibers from novel spinning solutions contaiuing acrylonitrile polymers,in which a major portion of the polymer is acrylonitrile, and a dyeassisting component comprising bentonite which has been modified bytreatment with an amine salt to produce a hydrophobic and organophiliccondition in place of the normal hydrophilic condition.

The presence of the modified bentonite in the filaments and fiberspermit dyeing to heavy shades by known methods with various celluloseacetate dyes, acid wool dyes, vat dyes, and direct cotton dyes. I

The ironing temperature or hot bar sticking temperature of the fiber israised substantially by the presence 7 j 'An object, therefore, of thepresent invention is to U provide acrylonitrile polymer fibers havinggreatly enhanced dye affinity for cellulose acetate dyes, acid wooldyes, vat dyes and direct cotton dyes.

Anotherobject of the invention is to provide a new method for preparingintimate mixtures of acrylonitrile polymers with a modified bentonitewhich has a hydrophobic and organophilic surface thereon. Another objectis to provide spinning solutions that contain dissolved acrylonitrilepolymersand highly dispersed particles of bentonite which have beentreated with an amine salt to produce an organophilic-surface thereon.;Still another object is to furnish acrylontrile polymer fibers havingan improved ironing or hot bar sticking te p ra re V Other objects willappear hereinafter. I

"-In accordance with the present inventionthese and other obj ects areattained by treating bentonite particles with 'an amine salt under.conditions that produce an organophilic surface on the bentoniteparticles. The treated bentonite is then dispersed in' a solution of theselected acrylonitrile polymer. In these dispersions, .the bentoniteparticles are so' small that they readily pass through filters andspinnerettes. Fibers spun, from the compositions by standard spinningprocedures can be dyed to heavy shades by various methods of dyeing withcellulose acetate dyes, acid wool dyes, vat dyes and cer tain directcotton dyes. The ironing temperature or hot bar sticking temperature ofthe fiber is also raised 20-30 C. by the presence ofthebentonite.

Bentonite is a colloidal clay mineral that solvates in water and becomeshighly dispersed. The natural product will not disperse in organicsolvents because the surface of the particles is highly organophobic.

Bentonite has, heretofore, been employed in connection with the spinningof filaments and fibers from spinhing solutions in a different mannerthan contemplated Patented Jan. 12,- 1960 ice deposits a superficiallayer of bentonite on the surface of the filament. This layer is readilylost during processing and has no effect on the ultimate properties ofthe fiber.

In contrast to that prior fiber surface treatment, the process of thepresent invention gives a product in which the bentonite which hasorganophilic properties is uniformly dispersed throughout the entirecross-section of the fiber.

In general, the organophilic bentonite is prepared by mixing a waterdispersion of bentonite with a water solu. tion of an amine salt. Theamine preferably contains at least 10 to 18 carbon atoms. An adsorbedlayer of amine is formed on the particle surface and the particlesbecome both hydrophobic and lose their ability to solvate with water, aswell as organophilic and hence acquire, however, the property ofsolvating with many types of organic liquids.

Suitable primary aliphatic amine salts for treating the bentoniteparticles are the hydrochlorides and acetate salts of decylamine,dodecylamine, hexadecyl and octadecylamine.

I have found that bentonite treated as described above disperses readilyin solvents such as dimethylformamide, dimethyl acetamide,gamma-butyrolacetone, ethylene carbonate, and succinodinitrile to givean ultimate particle size of one micron or less. The treated bentonitecan be added to solutions of acrylonitrile polymers in the types ofsolvents listed above. These solutions can be filtered, and then spun bythe wet or dry spinning methods without appreciable loss of bentonite.

Various well known Wet and dry spinning methods can be employed with mynovel spinning solutions. The wet or dry spinning methods described inEmmett V. Martin US. application Serial No. 159,089, filed April 29,1950, for Improvement in Spinning Acrylonitrile, now Patent 2,697,023 ofDecember 14, 1954, also may be employed to spin the spinningcompositions of the present invention. The resulting fibers have a hightensile strength and improved elastic properties. 7 V

I have found that bentonite treated with amines containing from 12 to 18carbon atoms is especially suitable for the process of the invention.The treated bentonite is mixed with solutions of acrylonitrile polymersby stirring. In some cases the dispersion rate is facilitated byheating. From 5% to 30% and preferably 8% to 15% of the treatedbentonite is employed based on the weight of the acrylonitrile polymer.

It has also been found that dispersion of the treated bentonite in theorganic solvent is aided by the presence of a glycol such as ethyleneglycol or diethylene glycol. For example, the wet precipitate of treatedbentonite may be mixed with the glycol and the water evaporated to leavea coating of glycolon the bentonite particles.

Polyacrylonitrile or acrylonitrile interpolymers .may be used in theprocess. The interpolymers should con tain at least acrylonitrile, and.preferably 87% to acrylonitrile. The following monomers are useful inthe preparation of interpolymers: vinyl acetate, methyl acetate, methylmethacrylate, isopropenyl acetate, vinyl chloride, methallyl alcohol,N-allyl acetamide, and methacrylonitrile. A particular useful class ofinterpolymers is derived from acrylamides as represented by: acrylamide,methacrylamide, N-methyl acrylamide, N-methyl methacrylamide,N-isopropyl acrylamide and N,N-di

polymer.

. 3 The present invention will be further illustrated in the followingexamples.

Example 1 A dodecyl amine complex of bentonite was prepared as follows:100 grams of bentonite was dispersed in 1500 cc. of water. Thedispersion was allowed to stand for 3 hours, then decanted from theresidue of grit and sand. A solution of 25 g. dodecyl aminehydrochloride in a mixture of 200 cc. of water and 200 cc. alcohol wasadded to the bentonite dispersion with good agitation. The bentonitesettled out as a fiocculant precipitate which was washed by decantation.After filtering, the precipi tate was dried at 50-60" C. The particlesof bentonite were coated with dodecyl amine. These treated particlesreadily dispersed when agitated and heated with solvents in whichacrylonitrile polymers are soluble such as: dimethylformamide, or withgamma-butyrolactone, or with dimethyl acetamide, or with ethylenecarbonate.

A spinning solution was prepared by dispersing 1.0 gram of this treatedbentonite in 40 cc. of dimethylformamide, then adding 8 g. ofpolyacrylonitrile. The solution was extruded through a multiholespinnerette into a coagulating bath consisting of 75 water-25dimethylformamide. The filaments were washed, dried, and drafted 600% at130160 C. The yarn had a strength of 2.0 grams per denier and anelongation of 16%. Different portions of this yarn were separately dyedwith the cellulose acetate dyes, acid wool dyes, vat dyes, and directcotton dyes. The acid wool dyes showed excellent .fastness tolaundering. These fibers had a hot bar sticking temperature of 250 -260C.

Example 2 A spinning solution was formed and spun into filaments dyedand otherwise processed as in Example 1 except that 2.0 grams of thetreated bentonite was added to the solution. Results comparable to thoseshown in Example 1 were obtained. 1

Example 3 Example 4 Bentonite is treatedwith octadecyl aminehydrochloride as described above in Example 1. Nine grams ofpolyacrylonitrile and 1.4 grams of the treated bentonite are stirredinto 50 cc. dimethylformamide with heating. Fibers are spun by extrusioninto an aqueous precipitating bath. The fibers dye well with celluloseacetate dyes, acid Wool dyes and vat dyes. They stick to the hot bar at265-275 C.

Example 5 One part of bentonite that has been treated by the method ofExample 1 with oleyl amine hydrochloride is mixed with 19 parts of apolymer having-the composition 90% acrylonitrile% isopropenyl acetate.Fibers spun from dimethyl acetamide solvent show excellent atfinity forthe above-mentioned cellulose acetate dyes, acid wool dyes and vat dyes.The fibers stick to the hot bar at 240-250 C.

Example 6 20 parts of bentonite that had been treated with octadecylamine acetate is mixed with 80 parts of a polymer having the composition95% acrylonitrile-5% N-methyl methacrylamide in butyrolactone solvent.Fibers spun by the dry spinning process from the mixture dye heavilywith the aforementioned acid wool dyes, cellulose acetate dyes, and vatdyes.

Example 7 Eight parts of bentonite that has been treated with octadecylamine hydrochloride by the process of Example 1 is mixed with 92 partsof an interpolymer having the composition acrylonitrile-10% N-isopropylacrylamide. Ethylene carbonate is used as solvent. Fibers spun by thedry spinning method from this mixture dye well with the aforesaid vatdyes, cellulose acetate dyes, acid wool dyes and direct cotton dyes.

Example 8 One part of bentonite that has been treated with oleyl aminehydrochloride by the method of Example 1 is mixed with 19 parts of apolymer having the composition 90% acrylonitrile-10% vinyl acetate.Fibers dry spun from dimethyl acetamide solvent show excellent aflinityfor the aforesaid cellulose acetate dyes, acid wool dyes, and vat dyes.The fibers stick to the hot bar at 240-250 C.

The following dyes are among those which can be employed to color thefibers of the present invention.

Cellulose acetate dyes:

Eastman Blue BGF Eastman Blue BNN Eastman Fast Violet SRLF Eastman FastYellow GLF Eastone Scarlet BG Eastone Orange 3R Color index Acid wooldyes: number Brilliant Milling Blue BA 37 Brilliant Milling Red RA 487Brilliant Milling Green B 667 Brilliant Milling Yellow 66 138 Fast LightYellow R 636 Scarlet 4RA Xylene Milling Black B 304 Vat dyes:

Ponsol Jade Green 1101 Ponsol Navy Blue RA 1100 Ponsol Red BND 1162Ponsol Violet RRD 1104 Ponsol Yellow 3R 452 Sulfanthrene Brown GR 121Mordant dyes:

Omega Chrome Brown 2R 98 Omega Chrome Dark Violet D 169 Omega ChromeOrange G 274 Omega Chrome Red B 652 Omega Chrome Yellow 3G 52 OmegaChrome Black P g 204 These cellulose acetate dyes, wool dyes, vat dyes,and mordant dyes may be applied to the fibers by the method shown inDiserens, Louis, Chem. & Tech. of Dyeing and Printing, New York, TheReinhold Corporation, vol. I (1948), vol. II (1951), translated from thesecond German edition.

I claim: 1

. 1. A synthetic spinning solution comprising an acrylonitrile polymerselected from the group consisting of polyacrylonitrile and copolymersof acrylonitrile with not more than 20% of mono-ethylenicallyunsaturated monomers in an organic solvent therefor containing adispersion of finely-divided bentonite having a surface coating thereonof a primary aliphatic amine having from 10 to 18 carbon atoms in thealkyl radical.

2. A synthetic spinning solution comprising an acrylonitrile polymerselected from the group consisting of polyacrylonitrile and copolymersof acrylonitrile with not more than 20% of mono-ethylenicallyunsaturated monomers'in an organic solvent therefor containing adispersion of finely-divided bentonite having a surface coating thereonof dodecyl amine.

3. A synthetic spinning solution comprising an acrylonitrile polymerselected from the group consisting of polyacrylonitrile and copolymersof acrylonitrile with not more than 20% of mono-ethylenicallyunsaturated monomers in an organic solvent therefor containing adispersion of finely-divided bentonite having a surface coating thereonof octadecyl amine.

4. A synthetic spinning solution comprising an acrylonitrile polymerselected from the group consisting of polyacrylonitrile and copolymersof acrylonitrile with not more than 20% of mono-ethylenicallyunsaturated monomers in an organic solvent therefor containing adispersion of finely-divided bentonite having a surface coating thereonof oleyl amine.

5. Synthetic fibers composed of an acrylonitrile polymer selected fromthe group consisting of polyacrylonitrile and copolymers ofacrylonitrile with not more than 20% of mono-ethylenically unsaturatedmonomers and containing finely-divided bentonite particles with acoating thereon consisting of a primary aliphatic amine having from -18carbon atoms in the alkyl radical.

6. Synthetic fibers composed of an acrylonitrile polymer selected fromthe group consisting of polyacrylonitrile and copolymers ofacrylonitrile with not more than 20% of mono-ethylenically unsaturatedmonomers and containing finely-divided bentonite particles with acoating thereon consisting of dodecyl amine.

7. Synthetic fibers composed of an acrylonitrile polymer selected fromthe group consisting of p'olyacro nitrile and copolymers ofacrylonitrile with not more than 20% of mono-ethylenically unsaturatedmonomers and containing finely-divided bentonite particles with acoating thereon consisting of octadecyl amine.

8. Synthetic fibers composed of an acrylonitrile polymer selected fromthe group consisting of polyacrylonitrile and copolymers ofacrylonitrile with not more than 20% of-mono-ethylenically unsaturatedmonomers and containing finely-divided bentonite particles with acoating thereon consisting of oleyl amine.

9. Synthetic fibers composed of polyacrylonitrile containing finelydivided bentonite particles which are coated with an organophiliccoating consisting of octadecyl amine.

10. A synthetic fiber spinning solution comprising polyacrylonitriledissolved in dimethylformamide and containing a dispersion of finelydivided bentonite having a surface coating thereon of dodecyl amine.

11. A synthetic fiber spinning solution comprising polyacrylonitriledissolved in gamma-butyrolactone and containing a dispersion of finelydivided bentonite having a surface coating thereon of octadecyl amine.

12. A synthetic fiber spinning solution comprising polyacrylonitriledissolved in dimethylformamide and containing a dispersion of finelydivided bentonite having a surface coating thereon of octadecyl amine.

13. A synthetic fiber spinning solution comprising acrylonitrile and 10%isopropenyl acetate dissolved in dimethyl acetamide and containing adispersion of finely divided bentonite having a surface coating thereonof oleyl amine.

14. A synthetic fiber spinning solution comprising acrylonitrile-5%N-methyl methacrylamide dissolved in butyrolactone and containing adispersion of finely divided bentonite having a surface coating thereonof octadecyl amine.

15. A synthetic fiber spinning solution comprising 90% acrylonitrile-10%N-isopropyl acrylamide dissolved in ethylene carbonate and containing adispersion of finely divided bentonite having a surface coating thereonof octadecyl amine.

16. A synthetic fiber spinning solution comprising 90% acrylonitrile-10%vinyl acetate dissolved in dimethyl acetamide and containing adispersion of finely divided bentonite having a surface coating thereonof oleyl amine.

References Cited in the file of this patent UNITED STATES PATENTS2,531,396 Carter Nov. 28, 1950 2,707,692 Hecht May 3, 1955 2,739,067Ratcliff Mar. 20, 1956 2,769,792 Ham Nov. 6, 1956 2,808,385 CaldwellOct. 1, 1957 FOREIGN PATENTS 675,627 Great Britain July 16, 1952 OTHERREFERENCES Journal of Physical & Colloid Chemistry, volume 53 (1949),article by J. W. Jordan, pages 294-305.

1. A SYNTHETIC SPINNING SOLUTION COMPRISING AN ACRYLONITRILE POLYMER SELECTED FROM THE GROUP CONSISTING OF POLYACRYLONTRILE AND COPOLYMERS OF ACRYLONTRILE WITH NOT MORE THAN 20% OF MONO-ETHYLENICALLY UNSATURATED MONOMERS IN AN ORGANIC SOLVENT THEREFOR CONTAINING A DISPERSION OF FINELY-DIVIDED BENTONTINE HAVING A SURFACE COATING THEREON OF A PRIMARY ALIPHATIC AMINE HAVING FROM 10 TO 18 CARBON ATOMS IN THE ALKYL RADICAL. 